A long acting analog of somatostatin, ocreotide, may be useful in the pre-operative management or, possibly, in avoiding surgery in infants and children with congenital hyperinsulinism who fail conventional medical therapy. Our previous studies of this agent indicate that, although all patients respond initially, the response to octreotide rapidly wanes. This tachyphylaxis probably reflects downregulation of B-cell somatostatin receptors. The present study examines whether responsiveness to octeotide can be maintained by employing lower starting and maintenance doses.